[doctorwho]

Just rebuild the sensitive portions of your code using movfuscator and leave the performance critical stuff alone. As long as everything is statically linked and you don't do anything stupid like "if (check) unlock()" that can be easily patched, it would make life pretty miserable for the RE crowd.

[ttoinou]

What's wrong with "if (check) unlock()" ? x)

[emiliobumachar]

It can be modified to "if (true) unlock()" relatively very easily, even in binary. No disassembling needed.